A Khmu ethnic minority man lights a fire to burn the dry vegetation on his field, Ban Non Boun Kang, Phongsaly province, Lao PDR. Swidden cultivation or ‘hai’ in Lao consists of cutting the natural vegetation, leaving it to dry and then burning it for temporary cropping of the land, the ash acting as a natural fertiliser. Shifting cultivation practices, although remarkably sustainable and adapted to their environment in the past, have come under increasing stress in recent decades and are now starting to be a major problem in Lao PDR, causing widespread deforestation and watershed degradation.